Titanium and Vanadium Catalysts with 2-Hydroxyphenyloxazoline and Oxazine Ligands for Ethylene-Norbornene (co)Polymerization
Round 1
Reviewer 1 Report
The paper brings a synthesis of new catalyst for the synthesis of polymers, in particular the use of vanadium as metal for these catalyst give excellent results in the formation of PET and also in the ethylene-norbornene co-polymerziatyion. In my opinion this argument is of good importance for a large part of chemists. As such it is suitable for publication after minor revision in Catalyst.
Author Response
I would thank very much Reviewers for their work and time spent on improving the submitted manuscript. All reviewers' comments have been taken into account.Reviewer 2 Report
This manuscript entitled: Titanium and vanadium catalysts with 2-hydroxyphenyloxazoline and oxazine ligands for ethylene-norbornene (co)polymerization describes the synthesis and catalytic acitivity of Ti and V complexes in ethylene polymerization. As mentioned in the introduction part the design of these ligand is similar to previous work, ref 34-36. The manuscript consists of the introduction and results obtained during ethylene polymerization and copolymerization with norbornene. I have no comments regarding performed experiment or presentation of experimental data, both are fine. I am also satisfied with compounds characterization. However, I would like to point out, that the introduction part say: … the proposed ligands differ with electron density because of the oxygen atom neighboring the C=N bond what should increase its stability through …(page 2, line 66-68). Unfortunately, I did not find and comparison between already published ligands (ref. 34-36) and the authors work. Please provide this comparison.
Since the paper describes catalytic activity of apparently novel ligands/catalysts for ethylene polymerization which is an interesting part of chemistry I would recommend to accept the manuscript for publication in catalysts after addressing the above-mentioned issue.
Author Response
I would thank very much Reviewers for their work and time spent on improving the submitted manuscript. All reviewers' comments have been taken into account. According to remark of Reviewer 2 some short comparison between already published Fujita type catalyst at similar reaction condition was made and the results was presented in Conclusion section. New references were added [45,46].Reviewer 3 Report
In this paper, a series of titanium and vanadium complexes with 1,3-oxazol-2-yl) phenol ligands were synthesized. The vanadium complexes were shown to be highly active in ethylene and ethylene/norbornene (co)polymerization. The highest activity reveals (L1)2VCl2 complex, activated by AlEt2Cl and in the presence of ETA, both in ethylene polymerization (7300 kgPE/(molV·h)) and ethylene/norbornene copolymerization. This paper concerns with production of the copolymer with Mw in the range of (2.6-0.9 x 105 g/mol) using cheap metal catalysts. This paper is of worth for publication in this Journal.
Small comments:
1) In line 16, “their structure” should be “their structures”
2) In line 171-172, “The studied catalysts produce the copolymer with Mw in the range of (2.6-0.9 x 105 g/mol) and its decrease of is observed especially for the catalyst with the ligand L2.” The sentence is not complete.
Author Response
I would thank very much Reviewers for their work and time spent on improving the submitted manuscript. All reviewers' comments have been taken into account. Small stylistic comments of Reviewer 3 was introduced. The whole manuscript was checked and numerous small grammatical changes were done both in the main text and Supplementary Material. The changes in the main text are highlighted by using the "Track Changes" function in Microsoft Word. In Supplementary Material also only small grammatical corrections were made.